The GemOro Testerossa Diamond Tester has intuitive finger grip pads for increased user-friendliness and ease of use. LED stone illumination and UV fluorescence detection. Precision retractable probe-tip with enhanced durability, and indestructible polycarbonate housing with molded rubber base for increased impact resistance if dropped. It features a glowing light bar/probe tip for quick stone identification (Green = Diamond, Blue = Moissanite, Yellow = Sapphire and Red = Metal Alert).